The present invention relates to fasteners. More particularly, the present invention relates to a two piece plastic fastener with both pieces being integrally molded as a single unit with the part or component being fastened. While the invention relates to the fastening of virtually any plastic component to another, the applicability of the invention to the automotive industry will be highlighted as it is particularly suited for utilization herein.
The automotive industry has in recent times been going through a downsizing and/or weight reducing effort due to several factors including the energy crisis, the cost of materials, government fuel efficiency mandates and the like. A major part of this downsizing and/or weight reduction effort has been to utilize to an ever-increasing extent components made from plastic materials.
Plastic parts are normally fastened to mating components by one or more separate individual fasteners. Industry is general and the automotive industry in particular utilize a wide variety and quantity of fasteners. These fasteners are made from a variety of materials but they have traditionally been made from steel or other metals. The cost to the automotive manufacturer for maintaining an individual active part number for each fastener used is substantial. By having a wide variety of fasteners in varying sizes, each particular fastener represents a separate part number with its attendant individual costs of ordering, tracking, inventory, quality control, service, and the like.
In addition to the cost of maintaining part numbers, the quality of the attachment when individual conventional fasteners are used in questionable. Such fasteners are normally affixed and tightened by some type of fastening gun, torque wrench, nut runner, automatic screw driver or other automated tool. These tools are operated either by working on the line or they may be operated by robots. Regardless of how such conventional fasteners are fastened, there is not a reliable means for insuring that the fastening procedure has been properly completed. Therefore, a substantial number of components complete the assembly process having improperly affixed or tightened fasteners.
Accordingly, it would be desirable to provide a fastening system which is light weight, reliable and capable of reducing the number of part numbers that need to be maintained by a manufacturer utilizing the system. The fastening system should also be simple and reliable to assemble to reduce the amount of labor necessary to complete the fastening process and the incidence of misapplied fasteners.